Pascal’s theorem: hexagon

Pascal’s hexagon

Blaise Pascal proved that for any hexagon inscribed in any conic section (ellipse, parabola, hyperbola) the three pairs of opposite sides when extended intersect in points that lie on a straight line. In the figure an irregular hexagon is inscribed in an ellipse. Opposite sides DC and FA, ED and AB, and FE and BC intersect at points on a line outside the ellipse.